The present invention relates generally to weight lifting exercise machines, and is particularly concerned with a cable and pulley linkage apparatus for coupling a load to various exercise stations in such a machine.
A typical exercise or weight machine has a support frame, a load such as a weight stack mounted on the frame, and various different exercise stations linked to the load, usually by means of a cable and pulley system consisting of a series of fixed and floating pulleys around which one or more cables extend. Such a machine is described in my U.S. Pat. No. 5,236,406, for example, the contents of which are incorporated herein by reference.
One problem with existing cable and pulley linkages is that a large number of pulleys is required to link a weight stack to several exercise stations, and the more pulleys you provide, the greater the space that is required. Additionally, there is a limit to the resistance ratio and the number of pulling points which can be achieved with current floating pulley arrangements. A 3 to 1 resistance ratio is the maximum which can be achieved in most current systems.
It is an objective of the present invention to provide a new and improved cable and pulley linkage system for weight lighting exercise machines.
According to one aspect of the present invention, a cable and pulley linkage system is provided, which comprises a floating double pulley having a support bracket and a pair of pulleys rotatably mounted on the same pivot axis on the support bracket in a side-by-side arrangement, a second floating pulley having at least one pulley, a first cable secured to the second floating pulley providing a first pulling point, a second cable secured to the double floating pulley providing a second pulling point, and a third cable extending around the single and double floating pulleys and providing third and fourth pulling points, whereby the system has at least four pulling points for selective linking to a load and exercise stations.
In one possible arrangement, the first cable is linked to a load such as a weight stack (100% load), the second cable is linked to a first exercise station, and the third cable extends around one of the pair of floating pulleys, then around the single floating pulley, and finally around the other of the pair of floating pulleys, providing two pulling points which may both be connected to exercise stations, or to one exercise station and one fixed point or cable tie-off, or to two cable tie-offs. In each case, the first exercise station has a 2 to 1 resistance ratio (200% of load), and the third cable has a 50% load at one or both ends.
In an alternative embodiment, a third pulley is secured to the double pulley support bracket beneath the pair of pulleys. In this case, the second cable extends around the third pulley to provide two pulling points at 100% of load each. These may both be connected to exercise stations, or one may be connected to a fixed cable tie-off.
The second floating pulley assembly may be a single pulley, or alternatively may comprise a pair of vertically aligned pulleys. In this case, the first cable extends around the uppermost pulley of the pair to provide two pulling points, one of which may be linked to the load or weight stack. This arrangement provides a 4 to 1 resistance ratio between the first cable and the second cable, where the first floating pulley assembly has a double pulley only. Alternatively, where a third pulley is mounted on the first floating pulley assembly, two pulling points at a 2 to 1 resistance ratio are provided. At the same time, the third cable in this arrangement provides two pulling points at 100% of load, or 1 to 1, and the first cable provides a third 100% pulling point.
According to another aspect of the present invention, a cable and pulley assembly is provided which comprises at least one floating pulley unit having a pulley housing and a pair of pulleys rotatably mounted side-by-side in the housing for rotation about a first pulley axis, a first cable linked to the pulley housing, a second cable extending around the pair of side by side pulleys and having opposite ends, and the resistance on the first cable being four times that at one end of the second cable.
In one alternative, the first cable is connected to the pulley housing at one end and has a resistance of four times that at one end of the second cable. In another alternative, a third pulley is rotatably mounted on the first pulley unit housing for rotation about a second pulley axis spaced from the first pulley axis, and the first cable extends around the third pulley and has opposite ends, the resistance at each end of the first cable being twice that at one end of the second cable. The third pulley axis is preferably perpendicular to the first pulley axis.
Each cable end may be selectively linked to an exercise resistance, a cable tie-off, or an exercise station. In some embodiments, a second floating pulley unit having a housing and a third pulley rotatably mounted in the housing is linked to the first floating pulley unit. The second cable extends around the third pulley, and a third cable is linked to the second pulley unit housing and to an exercise resistance, tie-off, or exercise station. The third cable may extend around a pulley rotatably mounted on the exercise resistance or weight stack, so that the end of the third cable may also be linked to an additional exercise station. In another alternative, the second cable extends from one of the side-by-side pulleys in a cable path extending around a pulley rotatably mounted on the weight stack or exercise resistance, and then back around the other of the side-by-side pulleys, so that the same cable links the first floating pulley unit to the load and still has opposite ends free for linking or connecting to different exercise stations.
This system permits five or more exercise stations to be linked to a resistance or load with a cable and pulley system where the pulleys are in line, on top of one another, rather than spreading out sideways as was necessary in the past. It therefore takes up much less space on the frame. Also, much fewer pulleys and pulley support brackets are required, and the streamlined design will enhance the appearance of the overall machine. The ability to provide two 2 to 1 resistance cables in one floating pulley was also not an option in previous systems.